Abstract: To digitally design heated tobacco products and to regulate aerosol formation, it is necessary to conduct an in-depth research on the heat transfer mechanism during the smoking process. A combined porous medium gas flow model and a gas-solid two-phase heat transfer model were established, and the temperature distribution in a model heated tobacco product was simulated for its puff-by-puff smoke formation. The accuracy of the model was verified by temperature measurement experiments. The results showed that: 1) The heat transfer model of the two-phase local heat balance could simulate the heat transfer processes of heated tobacco rod, and the difference between the simulated and tested temperatures of each section of the heated tobacco product was below 15 ℃. 2) The air flow field and the temperature field inside the heated tobacco product were simulated, the flow velocity of each section presented the periodicity distribution with each puffing, the flow velocity of the cavity section was the largest during puffing and there was basically no flow velocity around its periphery. The temperature of the tobacco rod presented a D-shaped distribution during a puffing period. 3) The maximum and the minimum heat fluxes of the heater and the tobacco rod periphery of the heated tobacco product were calculated, the heat release from the heater was about 39 J in a 2-s puffing period, and the heat loss around the tobacco rod periphery was about 33 J in a 2-s puffing period.